MixDACM and WMF-DAWHampel-Based FMCW Radar for Vital Sign Detection

In the field of life sign detection, the use of 77GHz Frequency Modulated Continuous Wave (FMCW) millimeterwave radar is being explored for non-contact monitoring of vital signs. This technology is challenged by interference from respiratory harmonics and clutter, which can result in abnormal phase values. An advanced algorithm for FMCW radar life sign signal detection is introduced in this study, combining first-order and second-order Difference of Arbitrary-Constant Multiplication (MixDACM) for phase unwrapping with a Windowed Median Filter-based Adaptive Weighted Hampel (WMFDAWHampel) method for managing outliers. The methodology involves utilizing the intermediate frequency signal from the FMCW radar to locate the target accurately. Subsequently, the MixDACM technique is applied for phase unwrapping, followed by the WMF-DAWHampel filter to address any residual abnormal phase values. Band-pass filters are then used to isolate the respiratory and heartbeat signals, facilitating the estimation of breathing and heart rates. Experimental results indicate that the integration of MixDACM and WMF-DAWHampel methods significantly improves phase unwrapping quality and outlier management. The integration of advanced signal processing techniques results in precise respiratory and heartbeat signal extraction, achieving estimation errors of 8.810% and 3.325%, respectively. Results from the study affirm the effectiveness of the proposed algorithm in boosting the precision of life sign detection through FMCW radar technology.